Photographic element with near-infrared antihalation layer

ABSTRACT

Disclosed is a photographic element comprising an antihalation dye of formula: ##STR1## wherein 
     X 1  . .,.!. .Iadd.and .Iaddend.X 2  independently represent. .s.!. --CR 8  R 9  --, --S--, --Se--, --NR 10  --, --CH═CH-- or --O--; 
     n is an integer of 2 or 3; 
     R 1  and R 2  independently represent alkyl of 1 to 10 carbons or substituted alkyl of 1 to 10 carbons; 
     R 3  represents . .a ring chosen from the set consisting of aryl, substituted aryl, and.!. a heterocyclic ring; 
     R 4 , R 5 , R 6  and R 7  independently represent hydrogen, alkyl of 1-10 carbons, substituted alkyl of 1-10 carbons. .,.!..Iadd.; or .Iaddend.R 4  and R 5  taken together or R 6  and R 7  taken together . .may.!. represent the atoms necessary to form a 5 or 6-membered aliphatic ring, an aromatic six-membered ring, an aromatic 10-membered ring, a substituted aromatic . .six-member.!. .Iadd.six-membered .Iaddend.ring or a substituted aromatic . .10-member.!. .Iadd.10-membered .Iaddend.ring; 
     R 8  . .,.!. .Iadd.and .Iaddend.R 9  independently represent alkyl of 1-10 carbons, substituted alkyl of 1-10 carbons, aryl of 6-10 carbons, substituted aryl of 6-10 carbons; 
     R 10  represents an alkyl of 1-10 carbons, substituted alkyl of 1-10 carbons, aryl of 6-10 carbons, substituted aryl of 6-10 carbons.Iadd.; and 
     Z represents CF 3  SO 3   - , Et 3  NH + , Na + , or K +  .Iaddend..

FIELD OF INVENTION

This invention relates to a photographic element which is particularlywell suited for use with a near-infrared laser. More specifically, thisinvention relates to a unique dye which can be used in the photographicelement. Even more specifically this invention relates to the use ofthese unique dyes in an antihalation layer of a photographic element.

BACKGROUND OF THE INVENTION

It is well known in the art of photographic science to add dyes to thestructure of a photographic element in such a way as to absorbdeleterious light. The dye can be located in several positionsincluding: between the exposure source and the photosensitive emulsion;between the photosensitive emulsion and the support; and on the oppositeside of the support to inhibit halation. Specific applications areillustrated, for example, in Research Disclosure, No. 308, December1989, Item 308119.

Antihalation is particularly important when a film is exposed with alaser such as in the use of long wavelength laser films for medicalimaging. The high intensity of long wavelength light (i.e.near-infrared) emitted by the laser is difficult to filter completely.If high levels of a dye are used it is typically difficult to remove thedye during processing and the result is a coloration, or dye stain,which is undesirable.

The development of the gallium-arsenic semiconductor laser, or diodelaser, is expected to extend the use of lasers for medical imaging intothe wavelength range of 780-830 nm. This application requires a filmwhich is sensitive in this wavelength range and has an antihalationlayer which absorbs in this region and is stable with time. Providedherein is a novel class of dyes which absorb throughout thenear-infrared region and are well suited for use as an antihalation dye.

SUMMARY Of THE INVENTION

A novel thioheterocyclic near-infrared absorbing dye is provided offormula ##STR2## wherein

X¹ . .,.!. .Iadd.and .Iaddend.X² independently represent. .s.!. --CR⁸ R⁹--, --S--, --Se--, --NR¹⁰ --, --CH═CH-- or --O--;

n is an integer of 2 or 3;

R¹ and R² independently represent alkyl of 1 to 10 carbons orsubstituted alkyl of 1 to 10 carbons;

R³ represents . .a ring chosen from the set consisting of aryl,substituted aryl, and.!. a heterocyclic ring;

R⁴, R⁵, R⁶ and R⁷ independently represent hydrogen, alkyl of 1-10carbons, substituted alkyl of 1-10 carbons. .,.!..Iadd.; or .Iaddend.R⁴and R⁵ taken together or R⁶ and R⁷ taken together . .may.!. representthe atoms necessary to form a 5 or 6-membered aliphatic ring, anaromatic six-membered ring, an aromatic 10-membered ring, a substitutedaromatic . .six-member.!. .Iadd.six-membered .Iaddend.ring or asubstituted aromatic . .10-member.!. .Iadd.10-membered .Iaddend.ring;

R⁸ . .,.!. .Iadd.and .Iaddend.R⁹ independently represent alkyl of 1-10carbons, substituted alkyl of 1-10 carbons, aryl of 6-10 carbons,substituted aryl of 6-10 carbons;

R¹⁰ represents an alkyl of 1-10 carbons, substituted alkyl of 1-10carbons, aryl of 6-10 carbons, substituted aryl of 6-10 carbons.Iadd.;and

Z represents CF₃ SO₃ ⁻, Et₃ NH⁺, Na⁺, or K⁺ .Iaddend..

DETAILED DESCRIPTION OF THE INVENTION

Dyes of the current invention are defined by the following formula:##STR3## wherein

X¹ . .,.!. .Iadd.and .Iaddend.X² independently represent. .s.!. --CR⁸ R⁹--, --S--, --Se--, --NR¹⁰ --, --CH═CH-- or --O--;

n is an integer of 2 or 3;

R¹ and R² independently represent alkyl of 1 to 10 carbons orsubstituted alkyl of 1 to 10 carbons;

R³ represents . .a ring chosen from the set consisting of aryl of 6-10carbons, substituted aryl of 6-10 carbons, and.!. a heterocyclic ring;

R⁴, R⁵, R⁶ and R⁷ independently represent hydrogen, alkyl of 1-10carbons, substituted alkyl of 1-10 carbons. .,.!..Iadd.; or .Iaddend.R⁴and R⁵ taken together or R⁶ and R⁷ taken together . .may.!. representthe atoms necessary to form a 5 or 6-membered aliphatic ring, anaromatic six-membered ring, an aromatic 10-membered ring, a substitutedaromatic . .six-member.!. .Iadd.six-membered .Iaddend.ring or asubstituted aromatic . .10-member.!. .Iadd.10-membered .Iaddend.ring;

R⁸ . .,.!. .Iadd.and .Iaddend.R⁹ independently represent alkyl of 1-10carbons, substituted alkyl of 1-10 carbons, aryl of 6-10 carbons,substituted aryl of 6-10 carbons;

R¹⁰ represents an alkyl of 1-10 carbons, substituted alkyl of 1-10carbons, aryl of 6-10 carbons, substituted aryl of 6-10 carbons.Iadd.;and

Z represents CF₃ SO₃ ⁻, Et₃ NH⁺, Na⁺, or K⁺ .Iaddend..

While not limited thereto a preferred compound is obtained when X¹ or X²is chosen from the set consisting of CR⁸ R⁹, S or NR¹⁰. Most preferredis X¹ or X² being CR⁸ R⁹.

A preferred compound is obtained when R¹ or R² represents an alkyl of 1to 5 carbons and most preferred is R¹ or R² substituted with a sulfonategroup or a carboxyl group.

The term "heterocyclic ring" refers specifically to the type present inphotographic emulsions. More specifically heterocyclic ring refers to aheterocyclic nuclei comprising 5 to 6 atoms in a heterocyclic ring.Preferably, R³ represents a heterocyclic ring composed of atoms selectedfrom the group consisting of C, N, O, S and Se. Specifically preferredexamples of heterocyclic rings of the types present in photographicemulsions are chosen from the . .set.!. .Iadd.group .Iaddend.consistingof:

the thiazole series; e.g. thiazole, 4-methylthiazole, 4-phenylthiazole,5-methylthiazole, 5-phenylthiazole, 4,5-dimethylthiazole, ..4,5l-diphenylthiazole.!. .Iadd.4,5-diphenylthiazole.Iaddend.,4-(2-thienyl)-thiazole;

the benzothiazole series; e.g., benzothiazole, 4-chlorobenzothiazole,5-chlorobenzothiazole, 6-chlorobenzothiazole, 7-chlorobenzothiazole,4-methylbenzothiazole, 5-methylbenzothiazole, 6-methylbenzothiazole,5-bromobenzothiazole, 6-bromobenzothiazole, 4-phenylbenzothiazole,5-phenylbenzothiazole, 4-methoxybenzothiazole, 5-methoxybenzothiazole,6-methoxybenzothiazole, 5-iodobenzothiazole, 6-iodobenzothiazole,4-ethoxybenzothiazole, 5-ethoxybenzothiazole, tetrahydrobenzothiazole,5,6-dimethoxybenzothiazole, 5,6-dioxymethylenebenzothiazole,5-hydroxybenzothiazole, 6-hydroxybenzothiazole;

the naphthothiazole series; e.g., naphtho 1,2!-thiazole, naphtho2,1!thiazole, 5-methoxynaphtho 2,1!-thiazole, 5-ethoxynaphtho2,1!thiazole, 8-methoxynaphtho 1,2!thiazole, 7-methoxynaphtho1,2!thiazole;

the thianaphtheno-7',6',4,5-thiazole series; e.g.4'-methoxythianaphtheno-7',6',4,5,thiazole;

the oxazole series; e.g., 4-methyloxazole, 5-methyloxazole,4-phenyloxazole, 4,5-diphenyloxazole, 4-ethyloxazole,4,5-dimethyloxazole, 5-phenyloxazole;

the benzoxazole series; e.g., benzoxazole, 5-chlorobenzoxazole,5-methylbenzoxazole, 5-phenylbenzoazole, 6-methylbenzoxazole,5,6-dimethylbenzoxazole, 4,5-dimethylbenzoxazole, 5-methoxybenzoxazole,5-ethoxybenzoxazole, 5-chlorobenzoxazole, 6-methoxybenzoxazole,5-hydroxybenzoxazole, 6-hydroxybenzoxazole;

the naphthoxazole series, e.g., naphtho 1,2!oxazole, naphtho2,1!oxazole;

the selenazole series; e.g., 4-methylselenazole, 4-phenylselenazole;

the benzoselenazole series; e.g., benzoselenazole,5-chlorobenzoselenazole, 5-methylbenzoselenazole,5-methoxybenzoselenazole, 5-hydroxybenzoselenazole,tetrahydrobenzoselenazole;

the naphthoselenazole series; e.g., naphthol 1,2!selenazole, naphtho2,1!selenazole;

the thiazoline series; e.g., thiazoline, 4-methylthiazoline;

the 2-quinoline series; e.g., quinoline, 3-methylquinoline,5-methylquinoline, 7-methylquinoline, 8-methylquinoline,6-chloroquinoline, 8-chloroquinoline, 6-methoxyquinoline,6-ethoxyquinoline, 6-hydroxyquinoline, 8-hydroxyquinoline;

the 4-quinoline series; e.g., quinoline, 6-methoxyquinoline,7-methoxyquinoline, 7-methylquinoline, 8-methylquinoline;

the 1-isoquinoline series; e.g., isoquinoline, 3,4-dihydroisoquinoline;

the 3-isoquinoline series; e.g., isoquinoline;

the benzimidazole series; e.g., 1,3-diethylbenzimidazole,1-ethyl-3-phenylbenzimidazole;

the 3,3-dialkylindolenine series; e.g., 3,3-dimethylindoline,3,3,5-trimethylindolenine, 3,3,7-trimethylindolenine;

the 2-pyridine series; e.g., pyridine, 5-methylpyridine; and the4-pyridine series; e.g., pyridine;

the 3,3-dialkylbenz e!indole series; e.g., 3,3-dimethylbenz e!indole;

the tetrazole series: e.g., 1-phenyltetrazole, 1-methyltetrazole;

the triazole series: e.g., 1-phenyl-triazole, 1-methyltriazole;

the pyrimidine series: e.g., pyrimidine; .Iadd.and .Iaddend.

the thiadiazole series: e.g., 1,3,4-thiadiazole.

Preferred compounds are obtained when R³ is chosen from the . .set.!..Iadd.group .Iaddend.consisting of:

the thiazole series; e.g. thiazole, 4-methylthiazole, 4-phenylthiazole,5-methylthiazole, 5-phenylthiazole, 4,5-dimethylthiazole, ..4,5l-diphenylthiazole.!. .Iadd.4,5-diphenylthiazole.Iaddend.,4-(2-thienyl)-thiazole;

the benzothiazole series; e.g., benzothiazole, 4-chlorobenzothiazole,5-chlorobenzothiazole, 6-chlorobenzothiazole, 7-chlorobenzothiazole,4-methylbenzothiazole, 5-methylbenzothiazole, 6-methylbenzothiazole,5-bromobenzothiazole, 6-bromobenzothiazole, 4-phenylbenzothiazole,5-phenylbenzothiazole, 4-methoxybenzothiazole, 5-methoxybenzothiazole,6-methoxybenzothiazole, 5-iodobenzothiazole, 6-iodobenzothiazole,4-ethoxybenzothiazole, 5-ethoxybenzothiazole, tetrahydrobenzothiazole,5,6-dimethoxybenzothiazole, 5,6-dioxymethylenebenzothiazole,5-hydroxybenzothiazole, 6-hydroxybenzothiazole;

the benzoxazole series; e.g., benzoxazole, 5-chlorobenoxazole,5-methylbenzoxazole, 5-phenylbenzoazole, 6-methylbenzoxazole,5,6-dimethylbenzoxazole, 4,5-dimethylbenzoxazole, 5-methoxybenzoxazole,5-ethoxybenzoxazole, 5-chlorobenzoxazole, 6-methoxybenzoxazole,5-hydroxybenzoxazole, 6-hydroxybenzoxazole;

the benzimidazole series; e.g., 1,3-diethylbenzimidazole,1-ethyl-3-phenylbenzimidazole;

the tetrazole series: e.g., 1-phenyltetrazole, 1-methyltetrazole;

the triazole series: e.g., 1-phenyl-triazole, 1-methyltriazole;

the pyrimidine series: e.g., pyrimidine; .Iadd.and .Iaddend.

the thiadiazole series: e.g., 1,3,4-thiadiazole.

The term "alkyl" is used herein in a manner consistent with the art todescribe a straight chain or branched hydrocarbon group. The term "aryl"is used herein in a manner consistent with the art to describe anaromatic cyclic six-membered ring such as a phenyl group or an aromatic10-membered ring such as a naphthalene group. The term "substitutedalkyl", as used herein, specifically refers to a straight or branchedalkyl which is substituted with at least one group such as sulfonate,carboxyl, hydroxy, halogen, --OL, where L is an alkyl or substitutedalkyl of 1-10 carbons, carbonylalkyl, amine or aryl. The most preferredsubstituent for alkyl is sulfonate or carboxyl. The term "substitutedaryl", as used herein, specifically refers to a six- or 10-membered ringwhich is substituted with at least one group such as sulfonate,carboxyl, hydroxy, halogen, --OL, where L is an alkyl or substitutedalkyl of 1-10 carbons, carbonylalkyl, amine, or aryl. The most preferredsubstituent for aryl is sulfonate or carboxylate. The term aromaticsix-membered ring refers to the atoms chosen from C, N, O and Snecessary to form an aromatic ring. Specifically preferred examplesinclude phenyl, pyridine, pyrimidine, pyrazine, and pyridazine. The termaromatic 10-membered ring refers to the atoms chosen from C, N, O and Snecessary to from an aromatic 10-membered ring. Specific examplesinclude quinoline, naphthalene, phthalazine, naphthyridine, quinoxaline,quinazoline, cinnoline, pteridine. The term 5 or 6-membered aliphaticring refers to the elements C, N, O and S necessary to form an aliphaticring. Specific examples include cyclopentane, cyclopentene, cyclohexane,cyclohexene, furan, pyran, pyrrole, pyrroline, pyrrolidine, piperidine,piperizine.

Exemplary dyes are provided in Table 1. Within Table 1, Y is defined bythe following structures: ##STR4##

When BMTD is used the dye is in the form of a dimer with BMTD acting asa bridging group between two chromophores.

Dyes of the current invention are prepared by known organic preparativetechniques in accordance with the following synthetic reaction: ##STR5##wherein R¹, R³, R⁴, R⁵, X¹, n, and . .Q.!. .Iadd.Z .Iaddend.are asdefined above. One of ordinary skill in the art would appreciate thatthe unsymmetrical dye could be prepared in an analogous manner bysubstituting one mole of the cyclic amine with a second cyclic amine asknown in the art.

The choice of cyclic amine represented by: ##STR6## will determine theterminal rings of the final dye. As such when X¹ or X² is intended to beCR⁸ R⁹ the proper starting material is an appropriately substitutedpyrrole or indole; when X¹ or X² is intended to be --S-- the properstarting material is an appropriately substituted thiazole,benzothiazole or naphthothiazole; when X¹ or X² is intended to be --Se--the proper starting material is an appropriately substituted selenazole,benzoselenazole or naphthselenazole; when X¹ or X² is intended to be--NR-- the proper starting material is an appropriately substitutedimidazole, benzimidazole, or naphthimidazole; when X¹ or X² is intendedto be --CH═CH-- the proper starting material is an appropriatelysubstituted pyridine, quinoline or benzquinoline; and when X¹ or X² isintended to be --O-- the proper starting material is an appropriatelysubstituted oxazole, benzoxazole or naphthoxazole.

The following detailed synthetic procedures are not intended to belimiting in any way. Other compounds described herein can be prepared inan analogous manner using standard organic synthetic procedures as knownin the art.

The antihalation layer comprises an absorbing amount of the antihalationdye represented by Formula 1 and can be present (1) on the opposite sideof the support from a photosensitive layer; (2) between thephotosensitive layer and the support; (3) supra to a photosensitivelayer or (4) between photosensitive layers. Other conventional layers,such as, for example, subbing layers, antistatic layers, overcoats,etc., may be present. These conventional layers may be present eitherbetween the photosensitive layer and/or the antihalation layer and thesupport, between the photosensitive layer and the antihalation layer inthe case in which both layers are present on the same side of thesupport, or on the side of the photosensitive layer and/or theantihalation layer away from the support.

The antihalation layer also comprises a vehicle. Such vehicles arewell-known in the art and include . .hyrophilic.!. .Iadd.hydrophilic.Iaddend.colloids, such as, for example a gelatin, which may be derivedfrom a variety of sources, such as, for example, cattle bone, pigskin,etc.; gelatin derivatives, such as, for example, phathalated gelatin,acetylated gelatin, etc.; polysaccharides, such as, for example,dextran, etc.; synthetic polymers, such as, for example, poly(vinylalcohol) and water soluble partially hydrolyzed poly(vinyl acetate);acrylic polymers; polymers of alkyl and sulfoalkyl acrylates andmethacraylates; polyamines; poly(vinyl acetals), such as, for example,poly(vinyl acetal), etc.; poly(vinyl ethers); etc. Gelatin is preferred.

To prepare the antihalation layer the dye can be dissolved in methanol,ethanol, water, or another suitable solvent, and added to an aqueousdispersion or melt of the vehicle. "An absorbing amount of theantihalation dye" means an amount of dye at least sufficient to impartantihalation properties to the layer yet not sufficient to cause anydeleterious side effects. For antihalation layers an optical density ofabout 0.40 at the wavelength used for imaging is preferred. Usingtechniques well known to those skilled in the art, the concentration ofdye required to attain this optical density can be calculated from thethickness of the antihalation layer and the absorption spectrum of theantihalation dye, which can be determined by conventionalspectrophotometric techniques. The dyes are typically present in theantihalation layer in an amount of 0.005 to 0.05 g/m², preferably 0.01to 0.03 g/m².

The photosensitive layer, or layers, of the photosensitive elementcomprises a component which is responsive to radiation. Thephotosensitive component is, preferably, a conventional gelatino silverhalide emulsion or a hydrophilic colloid silver halide emulsion.Conventional photographic silver halide emulsions employing any of thecommonly known halides, such as silver chloride, silver bromide, silveriodide, and mixtures thereof, may be used. These may be of variedcontent and may be negative and/or positive working.

The radiation sensitive layer also comprises a vehicle. Such vehiclesare well-known in the art and include the materials useful as vehiclesfor the antihalation layer, described above. A preferred vehicle isgelatin.

The layer may be hardened by addition of a conventional hardening agent,such as, for example, formaldehyde, glyoxal. Conventional additives mayalso be present for specific purposes, such as, for example, to enhanceand stabilize the response of the emulsion.

The preparation of silver halide emulsions is well known in the art.Silver halide emulsions, their preparation, and the preparation ofphotosensitive layers therefrom, are described in: Research Disclosure,Item 17643, December 1978; Research Disclosure, Item 18431, August 1979;Research Disclosure, Item 22534, January, 1983; and Abbot, U.S. Pat. No.4,425,425, the disclosures of which are incorporated by reference.

The photosensitive component may be sensitized to near-infrared bytechniques known in the art. Sensitization of silver halide may beaccomplished with chemical sensitizers, such as, for example, goldcompounds, iridium compounds, or with other group VIII metal compounds,or with spectral sensitizing dyes, such as for example, cyanine dyes,merocyanine dyes, styryls, etc.

The element may comprise any of a number of the other conventionaladditives and layers, such as are disclosed in any of the aboveincorporated references. These include, for example, optical brightners,antifoggants, emulsion stabilizers, image stabilizers, filter dyes,intergrain absorbers, light-scattering materials, gelatin hardeners,coating aids, surfactants, overcoat layers, interlayer and barrierlayers, antistat layers, plasticizers and lubricants, matting agents,development inhibitor-releasing compounds, etc. The element can beprepared by coating the layers onto the support using coating techniqueswhich are conventional in the art.

The film support may be any suitable transparent plastic. For example,the cellulosic supports, e.g. cellulose acetate, cellulose triacetate,cellulose mixed esters, etc. may be used. Polymerized vinyl compounds,e.g., copolymerized vinyl acetate and vinyl chloride, polystyrene, andpolymerized acrylates may also be mentioned. When polyethyleneterephthalate is manufactured for use as a photographic support, it ispreferable to use a mixed polymer subbing composition such as thattaught by Rawlins, U.S. Pat. No. 3,567,452, Miller, U.S. Pat. Nos.4,916,011 and 4,701,403, Cho, U.S. Pat. Nos. 4,891,308 and 4,585,730 andSchadt, U.S. Pat. No. 4,225,665. Upon completion of stretching andapplication of subbing composition, it is necessary to remove strain andtension in the base by a heat treatment comparable to the annealing ofglass.

STARTING MATERIALS

The following starting materials are used in the synthesis of the dyes.

Compound A

3H-Indolium, 2- 2- 2-chloro-3-(1,3-dihydro-1,3,3-trimethyl-2H-indol-2-ylidene)ethylidene!-1-cyclopenten-1-yl!ethenyl!-1,3,3-trimethyl-,salt with trifluoromethanesulfonic acid (1:1) is disclosed in Laganisand West, U.S. Pat. No. 4,882,265.

Compound B

1-(4-Sulfobutyl)-2,3,3-trimethylindolenium, inner salt2,3,3-Trimethylindolenine (16.0 g, 0.01 mol) was heated with 10.4 mlmelted 1,4-butanesultone and 20 ml o-xylene at 146° C. for 4 hours. Theorange solution was cooled to 60° C. before adding acetone to dilute andinduce crystallization. After cooling to room temperature, the productwas collected by filtration, washed with acetone, and dried to yield22.15 g of quaternary salt, mp 236° C.

Compound C

2-Chloro-3-(anilinomethylene)-1-(aniliniummethyl)cyclopent-1-enehydrochloride is disclosed by reference to Laganis and West, U.S. Pat.No. 4,882,265 and by reference to E.P. 0 420 012 A1.

Compound D

Compound B (4.58 g, 0.0155 mol), Compound C (2.69 g, 0.00775 mol), and60 ml dimethylformamide were mixed together. Acetic anhydride (4.14 ml)was added, followed by 2.4 g (0.024 mol) triethylamine. The mixture wasstirred at room temperature for 5.5 hrs. and then cooled to 0° C. beforefiltering. The filtrate was poured into 300 ml of stirred ethyl acetateand then chilled. After stirring overnight, the mixture was filtered andthe recovered solid reslurried twice with ethyl acetate. After filteringand drying, the yield was 4.25 g, mp 210° C., λ_(max) (methanol)=806(ε=265,000).

Compound E

2-Chloro-3-(hydroxymethylene)-1-formylcyclohex-1-ene Dimethylformamide(40 ml) and 40 ml dichloromethane were mixed and cooled to 5° C.Phosphorous oxychloride (33 ml) was dissolved in 40 ml dichloromethaneand added dropwise to the dimethylformamide/dichloro-methane solution ata rate sufficient to maintain the temperature below 25° C. Cyclohexanone(9 g) was added and the mixture heated to reflux for 5 hours. Aftercooling to room temperature, the reaction mixture was poured into 200 mlof ice and allowed to sit overnight. The quenched mixture was filteredto collect 9.62 g yellow crystals, mp 128° C., λ_(max) (methanol)=328 nm(ε=15,000).

Compound F

Compound E (2.16 g, 0.0125 mol), Compound B (7.38 g, 0.025 mol), and 30ml acetic acid were mixed together. Acetic anhydride (7 ml) was added,followed by 2.05 g (0.025 mol) anhydrous sodium acetate. The mixture washeated to reflux for 30 min., then cooled to room temperature andfiltered. The filtrate was poured into 300 ml ethyl acetate and allowedto sit 3 hours. The solvent was decanted and replaced by fresh ethylacetate. The mixture was agitated to break up the solid, filtered, andthe residue reslurried twice with ethyl acetate. After filtering anddrying, the yield was 6.55 g, mp 222° C.(dec), μ_(max) (methanol)=782 nm(ε=227,000).

Compound G

2,3,3-Trimethyl-(4-sulfobutyl)-1H-benzindolium, inner salt1,1,2-Trimethyl-1H-benzindole (184.47 g, 0.88 mol) was heated with 91.8ml liquid 1,4-butanesultone and 600 ml o-xylene at 144°-148° C. for 7.5hours. The greenish solution was cooled to 70° C. before adding 200 mlacetone to dilute and induce crystallization. After cooling to 13° C.,the product was collected by filtration, washed with acetone, andslurried twice in acetone. After filtering and drying, the yield was193.10 g of quaternary salt, mp 222° C.

Compound H

Compound G (171 g, 0.05 mol), Compound C (86 g, 0.25 mol), and 2000 mldimethylformamide were mixed together. Acetic anhydride (100 ml) wasadded. To the stirred mixture was added 75.5 g (0.75 mol) triethylamine.The mixture was carefully heated and held between 83°-90° C. for no morethan 6 minutes. The reaction cooled quickly with a methanol-ice bath to-3° C. The mixture was filtered to removed unreacted starting materialand the filtrate was then poured into 5000 ml of ethyl acetate. Themixture was chilled and stirred for at least three hours, then filtered,and the isolated product reslurried in ethyl acetate. After filtrationand drying, the yield was 173.10 g, mp 241° C., λ_(max) (methanol)=845nm (ε=250,000). A second crop of dye was recovered after letting theinitial ethyl acetate quench sit overnight: 4.75 g, mp 249° C., λ_(max)(methanol)=845 nm (ε=289,000).

Compound I

Compound E (1.72 g, 0.01 mol),6-Sulfo-1-(4-sulfobutyl)-2,3,3-trimethyl-1H-benzindolium, inner salt(NKX-1632 from Nippon Kankoh Shikiso, 8.27 g, 0.02 mol), and 30 mlacetic acid were mixed together. Acetic anhydride (7 ml) was added,followed by 4.1 g (0.05 mol) anhydrous sodium acetate. The mixture washeated to reflux for 21 min., then cooled to room temperature andfiltered. The filtrate was poured into 300 ml ethyl acetate and allowedto sit overnight. . .!.. The solvent was decanted and replaced by freshethyl acetate. The mixture was agitated to break up the solid, filteredand dried. The yield was 9.20 g, mp >350° C., λ_(max) (methanol)=821 nm(ε=226,000).

Compound J

Compound E (2.16 g, 0.0125 mol),5-Sulfo-1-(4-Sulfobutyl)-2,3,3-trimethylindolenium, inner salt (NKX-1653from Nippon Kankoh Shikiso, 9.38 g, 0.025 mol), and 30 ml acetic acidwere mixed together. Acetic anhydride (7 ml) was added, followed by 4.1g (0.05 mol) anhydrous sodium acetate. The mixture was heated to refluxfor 20 min., then cooled to room temperature and filtered. The filtratewas poured into 300 ml ethyl acetate to copiously precipitate solid.After stirring three hours, the mixture was filtered and the productreslurried in 150 ml ethyl acetate overnight. After filtering anddrying, the yield was 13.55 g., mp 298° C. (dec), λ_(max) (methanol)=789nm (ε=197,000).

Compound K

Compound C (4.3 g, 0.0125 mol),5-Sulfo-1-(4-Sulfobutyl)-2,3,3-trimethylindolenium, inner salt (NKX-1653from Nippon Kankoh Shikiso, 9.38 g, 0.025 mol), and 60 mldimethylformamide were mixed together. Acetic anhydride (6.6 ml) wasadded, followed by 5.6 g (0.055 mol) triethylamine. The mixture wasstirred at room temperature for 4.5 hours. The reaction mixture wasfiltered and the filtrate was poured into 200 ml ethyl acetate. Afterstirring at least one hour, the mixture was filtered and the productreslurried in ethyl acetate. After filtering and drying, the yield was11.91 g., mp 154°-187° C., λ_(max) (methanol)=811 nm (ε=251,000).

Compound L

3-Ethyl-2-methylbenzothiazolium iodide (11003 from H. W. Sands, 2.44 g,0.008 mol), Compound C (1.38 g, 0.04 mol), and 30 ml dimethylformamidewere mixed together. Acetic anhydride (2.0 ml) was added, followed by1.2 g (0.012 mol) triethylamine. The mixture was stirred at roomtemperature for 3 hrs. and then filtered. The collected gold-browncrystals were slurried overnight with ethyl acetate. After filtering anddrying, the yield was 1.80 g, mp 222° C., λ_(max) (methanol)=807(ε=196,000).

Compound M 1,3-Diallyl-2-methyl-4,5-quinoxalino-imidazolium4-toluenesulfonate

2,3-Bis-(3-allylamino)quinoxalinium 4-toluenesulfonate (16.48 g),prepared by reaction of allylamine with 2,3-dichloroquinoxaline, wasrefluxed with 40 ml acetic anhydride for two hours. After cooling toroom temperature, the reaction mixture was poured into 300 ml of stirreddiethyl ether. The resulting precipitate was broken up and trituratedwith ether until fine particles were obtained. Yield was 12.63 g, mp158° C.

Compound N

Compound M (17.46 g, 0.04 mol), Compound C (6.88 g, 0.02 mol), and 200ml dimethylformamide were mixed together. Acetic anhydride (10.4 ml) wasadded, followed by 6.0 g (0.06 mol) triethylamine. The mixture wasstirred at room temperature for 4.5 hrs. and then filtered. The filtratewas poured into 2000 ml of water, stirred for an hour, and filtered. Theproduct was reslurried in ethyl acetate, filtered and dried to yield14.31 g, mp 165°-173° C., λ_(max) (1% acetic acid/methanol)=846 nm(ε=165,000).

SYNTHESIS OF DYE COMPOUNDS Dye D-1

2,5-Dimercapto-1,3,4-thiadiazole, dipotassium salt (0.45 g, 0.002 mol)was mixed with 20 ml DMF. To this mixture was added 2.48 g (0.004 mol)of Compound A. After 1 hour, the reaction mixture was filtered and thenpoured into 200 ml of stirred water. After 60 minutes of stirring, themixture was filtered and the collected dye dried to give 2.28 g dye, mp208° C., λ_(max) (methanol)=741 nm (ε=241,000), 813 (ε=207,000).

Dye D-2

2-Mercaptopyrimidine (0.3 g, 0.0027 mol) was mixed with 10 ml DMF.Triethylamine (0.27 g, 0.0027 mol) was added. To this mixture was added1.0 g (0.00134 mol) of Compound F. The reaction was instantaneous. Thereaction mixture was filtered and then poured into 200 ml of stirredethyl acetate. After 60 minutes of stirring, the mixture was filtered.The product was collected, washed again with ethyl acetate, filtered anddried to give 1.08 g. dye, mp 120°-195° C. (dec), λ_(max) (methanol)=798nm (ε=170,000).

Dye D-3

2-Benzoxazolethiol (0.6 g, 0.004 mol) was mixed with 10 ml DMF.Triethylamine (0.4 g, 0.004 mol) was added. To this mixture was added1.5 g (0.002 mol) of Compound F. The reaction mixture was stirred 6.5hrs at room temperature, then filtered and poured into 200 ml of stirredethyl acetate. After 60 minutes of stirring, the mixture was filtered.The product was collected, washed again with ethyl acetate, filtered anddried to give 1.43 g dye, mp 195°-203° C. (dec), λ_(max) (methanol)=802nm (ε=207,000).

Dye D-4

4-Acetamidothiophenol (0.67 g, 0.004 mol) was mixed with 10 ml DMF.Sodium hydroxide (0.32 g, 0.008 mol) in 1 ml water was added. To thismixture was added 1.91 g (0.002 mol) of Compound J. The reaction wasstirred for forty minutes at room temperature. The reaction mixture wasfiltered and then poured into 200 ml of stirred ethyl acetate. Afterstirring one hour, the mixture was filtered and reslurried with ethylacetate. After filtering and drying, the yield was 2.54 g ,mp 245°-258°C., λ_(max) (methanol)=801 nm (ε=128,000). A purer sample was obtainedby slurrying 1 g of the product in ethyl acetate, adding 1 mlconcentrated hydrochloric acid to coagulate, decanting the solvent andredissolving the residue in methanol. The methanol solution was pouredinto 100 ml stirred ethyl acetate. After stirring 3 hours, theprecipitate was collected by filtration, washed with ethyl acetate, anddried to yield 0.87 g. mp 272° C.(dec), λ_(max) (methanol)=802 nm(ε=149,000).

Dye D-5

2-Mercaptopyrimidine (0.45 g, 0.004 mol) was mixed with 10 ml DMF.Sodium hydroxide (0.16 g, 0.004 mol) in 0.5 g water was added. To thismixture was added 1.91 g (0.002 mol) of Compound J. The reaction wasstirred 2 hrs at room temperature. The reaction mixture was filtered andthen poured into 200 ml of stirred ethyl acetate. After stirring twohours, the mixture was filtered and reslurried with ethyl acetate. Afterfiltering and drying, the yield was 2.12 g., 310° C. (dec), λ_(max)(methanol)=803 nm (ε=133,000).

Dye D-6

1-phenyl-1H-tetrazole-5-thiol, sodium salt (0.8 g, 0.004 mol) was mixedwith 10 ml DMF. To this mixture was added 1.5 g (0.002 mol) of CompoundF. The reaction mixture was stirred 4 hrs at room temperature, thenfiltered and then poured into 200 ml of stirred ethyl acetate. After 60minutes of stirring, the mixture was filtered. The product wascollected, washed again with ethyl acetate, filtered and dried to give1.64 g dye, mp 180° C. (dec), λ_(max) (methanol)=806 nm (ε=169,000).

Dye D-7

4-Methyl-4H,1,2,4-triazole-3-thiol (0.46 g, 0.004 mol) was mixed with 20ml DMF. Sodium hydroxide (0.16 g, 0.004 mol) in 1 ml water was added. Tothis mixture was added 1.91 g (0.002 mol) of Compound J. The reactionwas stirred one hour at room temperature. The reaction mixture wasfiltered and then poured into 200 ml of stirred ethyl acetate. Afterstirring one hour, the mixture was filtered and reslurried with ethylacetate. After filtering and drying, the yield was 1.75 g, 310° C.(dec), λ_(max) (methanol)=809 nm (ε=84,000).

Dye D-8

2-Benzoxazolethiol (0.61 g, 0.004 mol) was mixed with 10 ml DMF. Sodiumhydroxide (0.16 g, 0.004 mol) in 0.5 ml water was added. To this mixturewas added 1.91 g. (0.002 mol) of Compound J. The reaction was stirred3.5 hrs at room temperature. The reaction mixture was filtered and thenpoured into 200 ml of stirred ethyl acetate. After stirring two hours,the mixture was filtered and reslurried with ethyl acetate. Afterfiltering and drying, the yield was 1.71 g, 325° C. (dec), λ_(max)(methanol)=809 nm (ε=148,000).

Dye D-9

3-Amino-5-mercapto-1,2,4-triazole(0.93 g, 0.008 mol) was mixed with 20ml DMF. To this mixture was added 2.48 g (0.004 mol) of Compound A.After 3.5 hours, the reaction mixture was filtered and then poured into200 ml of stirred water. After 60 minutes of stirring, the mixture wasfiltered. The dye was collected and dried to give 2.36 g dye, mp 216°C., λ_(max) (methanol)=811 nm (ε=132,000).

Dye D-10

4-Acetamidothiophenol (2.68 g, 0.016 mol) was mixed with 40 ml DMF. Asolution of 0.64 g (0.016 mol) sodium hydroxide in 2 ml water was added.To this mixture was added 4.96 g (0.008 mol) of Compound A. After 1hour, the reaction mixture was filtered and then poured into 200 ml ofstirred water. After 60 minutes of stirring, the mixture was filtered.The product was collected and dried to give 6.69 g crude dye, mp70°-105° C., λ_(max) (methanol)=811 nm (ε=172,000).

Dye D-11

1-Phenyl-1H-tetrazole-5-thiol, sodium salt (0.80 g, 0.004 mol) was mixedwith 10 ml DMF. To this mixture was added 1.91 g (0.002 mol) of CompoundJ. The reaction was stirred 27 hrs at room temperature. The reactionmixture was filtered and then poured into 200 ml of stirred ethylacetate. After stirring three hours, the mixture was filtered andreslurried with ethyl acetate. After filtering and drying, the yield was0.80 g , 300° C. (dec), λ_(max) (methanol)=813 nm (ε=196,000).

Dye D-12

2,5-Dimercapto-1,3,4-thiadiazole, dipotassium salt (1.8 g, 0.008 mol)was mixed with 20 ml DMF. To this mixture was added 2.48 g (0.004 mol)of Compound A. After 1 hour, the reaction mixture was filtered and thenpoured into 200 ml of stirred water. After 60 minutes of stirring, themixture was filtered and the collected dye dried to give 1.44 g dye, mp215° C., λ_(max) (methanol)=819 nm (ε=257,000).

Dye D-13

2-Mercaptopyrimidine (0.9 g, 0.008 mol) was mixed with 20 ml DMF. Asolution of 0.32 g (0.008 mol) sodium hydroxide in 0.32 ml water wasadded. To this mixture was added 2.48 g (0.004 mol) of Compound A. Theabsorption of the solution instantaneously shifted from 797 nm to 819nm. The reaction mixture was filtered and then poured into 200 ml ofstirred water. After 60 minutes of stirring, the mixture was filteredand the collected dye dried to give 2.49 g dye, mp 245° C., λ_(max)(methanol)=819 nm (ε=229,000).

Dye D-14

2-Mercaptobenzimidazole (1.2 g, 0.008 mol) was mixed with 20 ml DMF. Asolution of 0.32 g (0.008 mol) sodium hydroxide in 0.32 ml water wasadded. To this mixture was added 2.48 g (0.004 mol) of Compound A. Theabsorption of the solution instantaneously shifted from 797 nm to 814nm. The reaction mixture was filtered and then poured into 200 ml ofstirred water. After 60 minutes of stirring, the mixture was filteredand the collected dye reslurried with isopropanol. After filtering anddrying, the yield was 1.48 g dye, mp 211°-215° C., λ_(max)(methanol)=819 nm (ε=38,000).

Dye D-15

4-Methyl-4H-1,2,4-triazole-3-thiol (0.92 g, 0.008 mol) was mixed with 20ml DMF. Triethylamine (0.81 g, 0.008 mol) was added. To this mixture wasadded 2.48 g (0.004 mol) of Compound A. After 50 minutes, the reactionmixture was filtered and then poured into 200 ml of stirred water. After60 minutes of stirring, the mixture was filtered. The product wascollected and dried to give 2.52 g dye, mp 149°-165° C., λ_(max)(methanol)=822 nm (ε=226,000).

Dye D-16

2-Mercaptopyrimidine (0.34 g, 0.003 mol) was mixed with 10 ml DMF. Tothis mixture was added 0.30 g (0.003 mol) triethylamine. After mixingwell, Compound D (0.91 g, 0.001 mol) was added. The reaction wasinstantaneous. The reaction mixture was filtered and then poured into200 ml of stirred ethyl acetate. After 120 minutes of stirring, themixture was filtered. The product was collected, washed again with ethylacetate, filtered and dried to give 0.76 g dye, mp 134°-145° C., λ_(max)(methanol)=823 nm (ε=220,000).

Dye D-17

4-Acetamidothiophenol (0.67 g, 0.004 mol) was mixed with 10 ml DMF.Triethylamine (0.404 g, 0.004 mol) was added. To this mixture was added2.35 g (0.002 mol) of Compound K. The reaction was stirred for fortyminutes at room temperature. The solvent was decanted and the residuedissolved in methanol. The solution was treated with 10 ml of 20%potassium acetate in methanol. The product immediately precipitated.After filtering and drying, the yield was 1.30 g, mp 310°.Iadd.C..Iaddend., λ_(max) (methanol)=823 nm (ε=164,000).

Dye D-18

2-Benzoxazolethiol (30.2 g, 0.02 mol) was mixed with 500 mldimethylformamide (DMF). A solution of 8.0 g (0.2 mol) sodium hydroxidein 16 ml water was added. To this mixture was added 62 g (0.1 mol) ofCompound A. The absorption of the solution instantaneously shifted from797 nm to 823 nm. The reaction mixture was filtered and then poured into1000 ml of stirred water. After 60 minutes of stirring, the mixture wasfiltered and the product vacuum-dried. The dry dye was stirred 60minutes with 200 ml methanol, filtered, and air-dried to give 49.31 g.dye, mp 139°-141° C., λ_(max) (methanol)=825 nm (ε=211,000).

Dye D-19

2-Mercaptobenzothiazole (1.34 g, 0.008 mol) was mixed with 20 ml DMF. Asolution of 0.32 g (0.008 mol) sodium hydroxide in 0.32 ml water wasadded. To this mixture was added 2.48 g (0.004 mol) of Compound A. After1 hour, the reaction mixture was filtered and then poured into 200 ml ofstirred water. After 60 minutes of stirring, the mixture was filtered.The dye was collected and dried to give 3.12 g, mp 70°-85° C., λ_(max)(methanol)=825 nm (ε=183,000).

Dye D-20

5-Mercapto-1-methyltetrazole sodium salt hydrate (1.11 g, 0.008 mol) wasmixed with 20 ml DMF. To this mixture was added 2.48 g (0.004 mol) ofCompound A. After 2.5 hours, the reaction mixture was filtered and thenpoured into 200 ml of stirred water. After 60 minutes of stirring, themixture was filtered. The product was collected and dried to give 2.67 gdye. The crude dye was rewashed with 5% aqueous sodium carbonate,filtered, and dried to give 2.44 g, mp 125°-144° C., λ_(max)(methanol)=828 nm (ε=196,000).

Dye D-21

Compound A (1.24 g, 0.002 mol) was mixed with1-phenyl-1H-tetrazole-5-thiol, sodium salt (0.752 g, 0.004 mol) in 10 mldimethylformamide (DMF). The absorption of the solution instantaneouslyshifted from 797 nm to 830 nm. The reaction mixture was filtered, thenpoured into 200 ml ether. The solvent was decanted and the residual oilrinsed with both ether and water. The oil was treated with a smallamount of methanol to solidify, then filtered and washed withisopropanol to collect 1.10 g golden crystals, mp 133°-140° C., λ_(max)(methanol)=829 nm (ε=197,000).

Dye-D-22

Compound A (2.48 g, 0.004 mol) was mixed with1-(4-hydroxyphenyl-1H-tetrazole-5-thiol (ORWO OB-1209, 1.55 g, 0.008mol) in 20 ml dimethylformamide (DMF) and 0.32 g sodium hydroxide in 1ml water. The absorption of the solution instantaneously shifted from797 nm to 829 nm. The reaction mixture was stirred for 20 min.,filtered, and then poured into 200 ml 5% aqueous potassium carbonate.The mixture was stirred for two hours and filtered. The collectedproduct was taken up in acetone, stirred, and filtered to yield 0.77 g,mp 197° C., λ_(max) =829 nm (ε=211,000). The acetone rinsings werepoured into 500 ml of 1% aqueous potassium carbonate, stirred 3 hours,filtered, and the product dried to give 1.58 g additional dye, mp173°-177° C., λ_(max) =828 nm (ε=203,000).

Dye D-23

1-Phenyl-1H-tetrazole-5-thiol, sodium salt (1.6 g, 0.008 mol) was mixedwith 10 ml DMF. To this mixture was added 1.47 g (0.002 mol) of CompoundD. The reaction was instantaneous. The reaction mixture was filtered andthen poured into 200 ml of stirred ethyl acetate. After 60 minutes ofstirring, the mixture was filtered. The product was collected, washedagain with ethyl acetate, filtered and dried to give 0.50 g dye, mp 185°C. (dec), λ_(max) (methanol)=838 nm (ε=164,000).

Dye D-24

2-Mercaptopyrimidine (0.45 g, 0.004 mol) was mixed with 10 ml DMF.Sodium hydroxide (0.16 g, 0.004 mol) in 0.5 g water was added. To thismixture was added 2.1 g (0.002 mol) of Compound I. The reaction wasstirred 5.5 hrs at room temperature. The reaction mixture was filteredand then poured into 200 ml of stirred ethyl acetate. After stirringovernight, the mixture was filtered and reslurried twice with ethylacetate. After filtering and drying, the yield was 2.18 g., mp >350° C.(dec), λ_(max) (methanol)=834 nm (ε=199,000).

Dye .Iadd.D-.Iaddend.25

2,5-Dimercapto-1,3,4-thiadiazole, dipotassium salt (0.23 g, 0.001 mol)was mixed with 20 ml DMF. To this mixture was added 2.10 g (0.002 mol)of Compound I. The reaction was stirred 5.5 hrs at room temperature,then 0.33 g sodium hydroxide in 1 ml water was added. The mixture wasstirred 16 hrs. at room temperature, then filtered. The filtrate waspoured into 200 ml of stirred ethyl acetate. After stirring two hours,the mixture was filtered and reslurried with ethyl acetate. Afterfiltering and drying, the yield was 2.15 g., 301° C. (dec), λ_(max)(methanol)=836 nm (ε=234,000), 765 nm (134,000).

. .dye.!. .Iadd.Dye .Iaddend.D-26

1-phenyl-1H-tetrazole-5-thiol, sodium salt (0.8 g, 0.004 mol) was mixedwith 10 ml DMF. To this mixture was added 0.91 g (0.001 mol) of CompoundH. The reaction was instantaneous. The reaction mixture was filtered andthen poured into 100 ml of stirred ethyl acetate. After 60 minutes ofstirring, the mixture was filtered. The product was collected, washedagain with ethyl acetate, filtered and dried to give 0.55 g dye, mp 285°C., λ_(max) (methanol)=879 nm (ε=252,000).

Dye D-27

1-Phenyl-1H-tetrazole-5-thiol, sodium salt (0.4 g, 0.002 mol) was mixedwith 10 ml DMF. To this mixture was added 0.6 g (0.00099 mol) CompoundL. After stirring six hours at room temperature, the reaction mixturewas filtered. The collected product was slurried with ethyl acetate,filtered and dried to give 0.48 g dye, mp 233°-234° C., λ_(max)(methanol)=844 nm (ε=209,000).

. .dye.!. .Iadd.Dye .Iaddend.D-28

1-Phenyl-1H-tetrazole-5-thiol, sodium salt (0.42 g, 0.002 mol) was mixedwith 10 ml DMF. To this mixture was added 0.78 g (0.001 mol) Compound N.After stirring 1.6 hours at room temperature, the reaction mixture wasfiltered. The filtrated was poured into 200 ml 5% aqueous potassiumcarbonate, stirred for three hours, then filtered and dried to give 0.69g dye, mp 138°-143° C. (dec), λ_(max) (1% acetic acid/methanol)=874 nm(ε=121,000).

                                      TABLE 1    __________________________________________________________________________    EXEMPLARY DYES    __________________________________________________________________________    INDOLENINE     ##STR7##                                       λ.sub.max nm    DYE    X    R       Y     Z      n (ε×10.sup.-5)    __________________________________________________________________________    D-1    H    CH.sub.3                        BMTD  CF.sub.3 SO.sub.3                                     2 741 (2.41)                        (2:1)*         813 (2.07)    D-2    H    (CH.sub.2).sub.4 SO.sub.3 .sup.-                        PYR   (Et.sub.3 NH.sup.+)                                     3 798 (1.69)    D-3    H    (CH.sub.2).sub.4 SO.sub.3 .sup.-                        MBO   (Et.sub.3 NH.sup.+                                     3 802 (2.07)    D-4    SO.sub.3 .sup.-                (CH.sub.2).sub.4 SO.sub.3 .sup.-                        SAR   3Na.sup.+                                     3 802 (1.49)    D-5    SO.sub.3 .sup.-                (CH.sub.2).sub.4 SO.sub.3 .sup.-                        PYR   3Na.sup.+                                     3 803 (1.33)    D-6    H    (CH.sub.2).sub.4 SO.sub.3 .sup.-                        PMT    Na.sup.+                                     3 806 (1.69)    D-7    SO.sub.3 .sup.-                (CH.sub.2).sub.4 SO.sub.3 .sup.-                        MTT   3Na.sup.+                                     3 809 (0.83)    D-8    SO.sub.3 .sup.-                (CH.sub.2).sub.4 SO.sub.3 .sup.-                        MBO   3Na.sup.+                                     3 809 (1.48)    D-9    H    CH.sub.3                        AMT   CF.sub.3 SO.sub.3 .sup.-                                     2 811 (1.31)    D-10   H    CH.sub.3                        SAR   CF.sub.3 SO.sub.3 .sup.-                                     2 811 (1.71)    D-11   SO.sub.3 .sup.-                (CH.sub.2).sub.4 SO.sub.3 .sup.-                        PMT   3Na.sup.+                                     3 813 (1.96)    D-12   H    CH.sub.3                        BMTD  CF.sub.3 SO.sub.3 .sup.-                                     2 819 (2.57)                        (1:1)**                              (1:1)**    D-13   H    CH.sub.3                        PYR   CF.sub.3 SO.sub.3 .sup.-                                     2 819 (2.29)    D-14   H    CH.sub.3                        MBI   CF.sub.3 SO.sub.3 .sup.-                                     2 819 (0.38)    D-15   H    CH.sub.3                        MTT   CF.sub.3 SO.sub.3 .sup.-                                     2 823 (2.18)    D-16   H    (CH.sub.2).sub.4 SO.sub.3 .sup.-                        PYR   (Et.sub.3 NH.sup.+)                                     2 823 (2.19)    D-17   SO.sub.3 .sup.-                (CH.sub.2).sub.4 SO.sub.3 .sup.-                        SAR   3K.sup.+                                     2 823 (1.64)    D-18   H    CH.sub.3                        MBO   CF.sub.3 SO.sub.3 .sup.-                                     2 825 (2.11)    D-19   H    CH.sub.3                        MBT   CF.sub.3 SO.sub.3 .sup.-                                     2 825 (1.83)    D-20   H    CH.sub.3                        MMTE  CF.sub.3 SO.sub.3 .sup.-                                     2 828 (1.96)    D-21   H    CH.sub.3                        PMT   CF.sub.3 SO.sub.3 .sup.-                                     2 829 (1.97)    D-22   H    CH.sub.3                        HPMT  CF.sub.3 SO.sub.3 .sup.-                                     2 829 (2.11)    D-23   H    (CH.sub.2).sub.4 SO.sub.3 .sup.-                        PMT   Na.sup.+                                     2 838 (1.64)    __________________________________________________________________________    BENZINDOLES     ##STR8##                                      λ.sub.max nm    DYE     X    R       Y     Z    n (ε×10.sup.-5)    __________________________________________________________________________    D-24    SO.sub.3 .sup.-                 (CH.sub.2).sub.4 SO.sub.3 .sup.-                         PYR   3Na.sup.+                                    3 834 (2.00)    D-25    SO.sub.3 .sup.-                 (CH.sub.2).sub.4 SO.sub.3 .sup.-                         BMTD  3Na.sup.+                                    3 836 (2.34)                         (2:1)*       736 (1.33)    D-26    H    (CH.sub.2).sub.4 SO.sub.3 .sup.-                         PMT   Na.sup.+                                    2 879 (2.52)    __________________________________________________________________________    BENZOTHIAZOLE     ##STR9##    D-27 λ.sub.max = 844 nm (ε = 209,000)    QUINOXALINE     ##STR10##    D-28 λ.sub.max = 874 nm (ε = 121,000)    __________________________________________________________________________     *Two thioether links     **One thioether link

EXAMPLE 1 Preparation of Antihalation Backing Solution

A 7% gelatin solution is made by cold soaking and then dissolving drygelatin in water. This solution contains the ingredients as tabulatedbelow:

    ______________________________________    deionized water          1900 g    dry gelatin              200 g    5% polymethacrylate beads in a                             50 g    4% aqueous gelatin solution    3N sulfuric acid         10 g    16.5% aqueous Triton ® X-200 (28%)                             100 g    (trademark of Union Carbide Corp.)    Lensodel ® HB7       2 g    (trademark of Shell Corp.)    10.2% aqueous Fluorad ® FC-129                             8 g    (trademark of 3M Corp.)    10% aqueous Oxonol Red 536 Pina ®                             25 g    (trademark of Riedel de Haen A.G.)    3.7% Aqueous formaldehyde                             50 g    Aqueous or alcoholic dye solution                             up to 250 g    ______________________________________

The above-prepared coating solution containing 7% gelatin in water inthen applied to a 0.007 inch polyethylene terephthalate substratesuitably subbed as described in Alles U.S. Pat. No. 2,779,684.Formaldehyde hardener is added into the gelatin solution. The coatedlayer is passed through a film dryer where cold air first sets thegelatin and then warm dry air removes the moisture and alcohol. Theresulting antihalation layer contains 4.0 g gelatin/sq. meter. In thefollowing tables the symbols F, D, J, K, I and L refer to the Compoundsin the section STARTING MATERIAL. ##STR11## Optical densities found forthese dyes in this antihalation layer is shown in Table 2.

                  TABLE 2    ______________________________________    Optical densities of antihalation layer    at NIR laser wavelengths.            λ.sub.max                    amt      Optical Densities    Dye     film    (mg/m.sup.2)                             @λ.sub.max                                   780 nm                                         820 nm                                               830 nm    ______________________________________    F       797     32.7     0.643 0.544 0.425 0.38    D-2     811     33.2     0.561 0.345 0.53  0.425    D-3     816     33.8     0.571 0.33  0.565 0.505    D-6     825     34       0.500 0.29  0.50  0.466    D       823     23.9     0.535 0.245 0.532 0.516    D-16    848     24.5     0.44  0.205 0.298 0.357    J       806     33.8     0.573 0.37  0.427 0.267    D-5     819     34       0.400 0.185 0.397 0.385    D-7     824     50       0.518 0.265 0.511 0.504    D-8     826     35       0.40  0.20  0.4   0.4    D-11    827     26.2     0.339 0.157 0.326 0.337    K       827     34       0.51  0.233 0.495 0.505    C-1     824     24       0.476 0.257 0.474 0.456    I       838     34       0.515 0.255 0.423 0.49    D-24    853     33.9     0.383 0.175 0.255 0.295    D-25    856     34       0.195 0.157 0.141 0.157    D-26    885     16.7     0.235 0.12  0.128 0.131    C-2     839     34       0.284 0.123 0.237 0.268    L       705     93.8     0.198 0.139 0.0725                                               0.054    ______________________________________

The example clearly shows the dyes of this invention have superior andmore efficient light-absorbing properties than the well-knowncomparative Compound L. All dyes of this invention provide higheroptical density at dye levels significantly lower than comparativeCompound L. This provides economic benefit since desired antihalationoptical densities can be obtained at much lower dye levels compared tocomparative Compound L. The dyes of this invention provide absorptionwhich is more suitable and optimally balanced for use with lasersemitting at 820 and 830 nm.

EXAMPLE 2

The antihalation layer was prepared as in example 1. The films weretested for post-processing stain by processing the film at 90 sec. at34° C. in DuPont MD developer and MF fixer. Residual dye stain isreported as per cent of fresh optical density. Fading of the films arereported as per cent of optical density after 3 days accelerated agingat 50° C. and 60% relative humidity. The results obtained are presentedin Table 3.

                  TABLE 3    ______________________________________    Ageing results of Antihalation Layer             λ.sub.max (film)                       O.D.    Dye      nm        fresh      % Stain                                         % Fading    ______________________________________    F        797       0.643      58     95    D-2      811       0.561      24     95    D-3      816       0.571      36     91    D-6      819       0.5        39     97    D        823       0.535      46     53    D-16     848       0.44       17     75    J        804       0.57       9      89    D-5      819       0.408      12     96    D-7      824       0.518      11     104    D-11     827       0.339      18     105    D-8      824       0.4        15     100    K        827       0.51       15     46    C-1      824       0.476      72     86    I        838       0.515      50     108    D-24     853       0.383      32     104    D-25     854       0.195      46     101    D-26     898       0.12       45     60    C-2      839       0.234      63     102    ______________________________________

The example clearly shows that the dyes of this invention provideimprovement in dye stain and/or fading characteristics compared toCompounds F and D. ##STR12##

. .I.!. .Iadd.We .Iaddend.claim:
 1. A photographic element comprising.Iadd.a photosensitive silver halide emulsion layer and .Iaddend.anabsorbing amount of the antihalation dye:wherein X¹ . .,.!. .Iadd.and.Iaddend.X² independently represent. .s.!. --CR⁸ R⁹ --, --S--, --Se--,--NR¹⁰ --, --CH═CH-- or --O--; n is an integer of 2 or 3; R¹ and R²independently represent alkyl of 1 to 10 carbons or substituted alkyl of1 to 10 carbons; R³ represents . .a ring chosen from the set consistingof aryl, substituted aryl, and.!. a heterocyclic ring.Iadd., saidheterocyclic ring being a substituted or unsubstituted 5- or 6-memberedheterocyclic ring containing hetero atoms selected from the groupconsisting of nitrogen, oxygen, sulfur, and selenium.Iaddend.; R⁴, R⁵,R⁶ and R⁷ independently represent hydrogen, alkyl of 1-10 carbons,.Iadd.or .Iaddend.substituted alkyl of 1-10 carbons. .,.!..Iadd.; or.Iaddend.R⁴ and R⁵ taken together or R⁶ and R⁷ taken together . .may.!.represent the atoms necessary to form a 5 or 6-membered aliphatic ring,an aromatic six-membered ring, an aromatic 10-membered ring, asubstituted aromatic . .six-member.!. .Iadd.six-membered .Iaddend.ringor a substituted aromatic . .10-member.!. .Iadd.10-membered.Iaddend.ring; R⁸ . .,.!. .Iadd.and .Iaddend.R⁹ independently representalkyl of 1-10 carbons, substituted alkyl of 1-10 carbons, aryl of 6-10carbons, .Iadd.or .Iaddend.substituted aryl of 6-10 carbons; R¹⁰represents an alkyl of 1-10 carbons, substituted alkyl of 1-10 carbons,aryl of 6-10 carbons, .Iadd.or .Iaddend.substituted aryl of 6-10carbons.Iadd.; and Z represents CF₃ SO₃ ⁻, Et₃ NH⁺, Na⁺, or K⁺.Iaddend..
 2. The photographic element recited in claim 1 wherein . .R³is.!. .Iadd.X¹ or X² represent .Iaddend.CR⁸ R⁹ ; R⁸ and R⁹ independentlyrepresent alkyl of 1-10 carbons, substituted alkyl of 1-10 carbons, arylof 6-10 carbons, substituted aryl of 6-10 carbons.
 3. The photographicelement recited in claim 1 wherein at least one of R¹ and R² is an alkylof 1 to 10 carbon atoms substituted with sulfonate or . .carbonate.!..Iadd.carboxylate.Iaddend..
 4. The photographic element recited in claim1 wherein R⁴ and R⁵ or R⁶ and R⁷ are taken together to form asix-membered aromatic ring or a 10-membered aromatic ring.
 5. Thephotographic element recited in claim 4 wherein said six-memberedaromatic ring or said 10-membered aromatic ring is substituted withsulfonate or carboxylate.
 6. The photographic element recited in claim 1wherein R¹ or R² is an alkyl of 1-10 carbon atoms substituted with asulfonate or carboxylate and at least one combination of R⁴ and R⁵ or R⁶and R⁷ are taken together to form a six-membered aromatic ring or a10-membered aromatic ring wherein said six-membered aromatic ring orsaid 10-membered aromatic ring is substituted with a sulfonate or acarboxylate.
 7. The photographic element recited in claim 6 wherein saidR¹ or R² is alkyl of 1-5 carbon. .s.!. atoms.
 8. The photographicelement recited in claim 1 wherein said R³ is chosen from the . .set.!..Iadd.group .Iaddend.consisting of pyrimidine, benzoxazole,phenyltetrazole, and methyltriazole.
 9. A photographic elementcomprising .Iadd.a photosensitive silver halide emulsion layer and.Iaddend.a dye of formula: ##STR13## whereinX¹ . .,.!. .Iadd.and.Iaddend.X² independently represent. .s.!. --CR⁸ R⁹ --, --S--, --Se--,--NR¹⁰ --, --CH═C-- or --O--; n is 2; R¹ and R² independently representalkyl of 1 to 10 carbons or substituted alkyl of 1 to 10 carbons; R³represents . .a ring chosen from the set consisting of aryl, substitutedaryl, and.!. a heterocyclic ring.Iadd., said heterocyclic ring being asubstituted or unsubstituted 5- or 6-membered heterocyclic ringcontaining hetero atoms selected from the group consisting of nitrogen,oxygen, sulfur, and selenium.Iaddend.; R⁴, R⁵, R⁶ and R⁷ independentlyrepresent hydrogen, alkyl of 1-10 carbons, .Iadd.or .Iaddend.substitutedalkyl of 1-10 carbons. .,.!..Iadd.; or .Iaddend.R⁴ and R⁵ taken togetheror R⁶ and R⁷ taken together . .may.!. represent the atoms necessary toform a 5 or 6-membered aliphatic ring, an aromatic six-membered ring, anaromatic 10-membered ring, a substituted aromatic . .six-member.!..Iadd.six-membered .Iaddend.ring or a substituted aromatic ..10-member.!. .Iadd.10-membered .Iaddend.ring; R⁸ . .,.!. .Iadd.and.Iaddend.R⁹ independently represent alkyl of 1-10 carbons, substitutedalkyl of 1-10 carbons, aryl of 6-10 carbons, .Iadd.or.Iaddend.substituted aryl of 6-10 carbons; R¹⁰ represents an alkyl of1-10 carbons, substituted alkyl of 1-10 carbons, aryl of 6-10 carbons,.Iadd.or .Iaddend.substituted aryl of 6-10 carbons.Iadd.; and Zrepresents CF₃ SO₃ ⁻, Et₃ NH⁺, Na⁺, or K⁺ .Iaddend..
 10. A photographicelement comprising .Iadd.a photosensitive silver halide emulsion layerand .Iaddend.a dye of formula: ##STR14## whereinX¹ . .,.!. .Iadd.and.Iaddend.X² independently represent. .s.!. --CR⁸ R⁹ --, --S--, --Se--,--NR¹⁰ --, --CH═CH-- or --O--; n is 3; R¹ and R² independently representalkyl of 1 to 10 carbons or substituted alkyl of 1 to 10 carbons; R³represents . .a ring chosen from the set consisting of aryl, substitutedaryl, and.!. a heterocyclic ring.Iadd., said heterocyclic ring being asubstituted or unsubstituted 5- or 6-membered heterocyclic ringcontaining hetero atoms selected from the group consisting of nitrogen,oxygen, sulfur, and selenium.Iaddend.; R⁴, R⁵, R⁶ and R⁷ independentlyrepresent hydrogen, alkyl of 1-10 carbons, .Iadd.or .Iaddend.substitutedalkyl of 1-10 carbons. .,.!..Iadd.; or .Iaddend.R⁴ and R⁵ taken togetheror R⁶ and R⁷ taken together . .may.!. represent the atoms necessary toform a 5 or 6-membered aliphatic ring, an aromatic six-membered ring, anaromatic 10-membered ring, a substituted aromatic . .six-member.!..Iadd.six-membered .Iaddend.ring or a substituted aromatic ..10-member.!. .Iadd.10-membered .Iaddend.ring; R⁸ . .,.!. .Iadd.and.Iaddend.R⁹ independently represent alkyl of 1-10 carbons, substitutedalkyl of 1-10 carbons, aryl of 6-10 carbons, .Iadd.or.Iaddend.substituted aryl of 6-10 carbons; R¹⁰ represents an alkyl of1-10 carbons, substituted alkyl of 1-10 carbons, aryl of 6-10 carbons,.Iadd.or .Iaddend.substituted aryl of 6-10 carbons.Iadd.; and Zrepresents CF₃ SO₃ ⁻, Et₃ NH⁺, Na⁺, or K⁺ .Iaddend.. .Iadd.
 11. Thephotographic element recited in claim 7 wherein said X¹ and X² are thesame..Iaddend..Iadd.12. The photographic element recited in claim 1wherein X¹ and X² are chosen from the group consisting of --CR⁸ R⁹ --,S, and NR¹⁰..Iaddend..Iadd.13. The photographic element recited in claim3 wherein said X¹ and X² are the same..Iaddend..Iadd.14. Thephotographic element recited in claim 13 wherein said heterocyclic ringis selected from the group consisting of thiazole, benzothiazole,benzoxazole, benzimidazole, tetrazole, triazole, pyrimidine, andthiadiazole..Iaddend..Iadd.15. The photographic element recited in claim14 wherein R¹ or R² is an alkyl of 1-5 carbon atoms substituted withsulfonate or carboxylate and at least one combination of R⁴ and R⁵ or R⁶and R⁷ are taken together to form a six-membered or 10-membered aromaticring wherein said six-membered or 10-membered aromatic ring issubstituted with a sulfonate or a carboxylate..Iaddend..Iadd.16. Thephotographic element recited in claim 1 wherein said heterocyclic ringis selected from the group consisting of thiazole, benzothiazole,naphthothiazole, thianaphtheno-7',6',4,5-thiazole, oxazole, benzoxazole,naphthoxazole, selenazole, benzoselenazole, naphthoselenazole,thiazoline, 2-quinoline, 4-quinoline, 1-isoquinoline, 3-isoquinoline,benzimidazole, 3,3-dialkylindolenine, 2-pyridine, 3,3-dialkylbenzindole,tetrazole, triazole, pyrimidine, and thiadiazole..Iaddend..Iadd.17. Thephotographic element recited in claim 16 wherein said X¹ and X² are thesame..Iaddend..Iadd.18. The photographic element recited in claim 17wherein R¹ or R² is an alkyl of 1-5 carbon atoms substituted withsulfonate or carboxylate and at least one combination of R⁴ and R⁵ or R⁶and R⁷ are taken together to form a six-membered or 10-membered aromaticring wherein said six-membered or 10-membered aromatic ring issubstituted with a sulfonate or a carboxylate..Iaddend..Iadd.19. Thephotographic element recited in claim 9 wherein X¹ and X² are chosenfrom the group consisting of --CR⁸ R⁹ --, S, and NR¹⁰..Iaddend..Iadd.20.The photographic element recited in claim 19 wherein said X¹ and X² arethe same..Iaddend..Iadd.21. The photographic element recited in claim 20wherein said heterocyclic ring is selected from the group consisting ofthiazole, benzothiazole, benzoxazole, benzimidazole, tetrazole,triazole, pyrimidine, and thiadiazole..Iaddend..Iadd.22. Thephotographic element recited in claim 9 wherein said heterocyclic ringis selected from the group consisting of thiazole, benzothiazole,naphthothiazole, thianaphtheno-7',6',4,5-thiazole, oxazole, benzoxazole,naphthoxazole, selenazole, benzoselenazole, naphthoselenazole,thiazoline, 2-quinoline, 4-quinoline, 1-isoquinoline, 3-isoquinoline,benzimidazole, 3,3-dialkylindolenine, 2-pyridine, 3,3-dialkylbenzindole,tetrazole, triazole, pyrimidine, and thiadiazole..Iaddend..Iadd.23. Thephotographic element recited in claim 22 wherein said X¹ and X² are thesame..Iaddend..Iadd.24. The photographic element recited in claim 1wherein said X¹ and X² are the same..Iaddend..Iadd.25. The photographicelement recited in claim 10 wherein X¹ and X² are chosen from the groupconsisting of --CR⁸ R⁹ --, S, and NR¹⁰..Iaddend..Iadd.26. Thephotographic element recited in claim 25 wherein said X¹ and X² are thesame..Iaddend..Iadd.27. The photographic element recited in claim 26wherein said heterocyclic ring is selected from the group consisting ofthiazole, benzothiazole, benzoxazole, benzimidazole, tetrazole,triazole, pyrimidine, and thiadiazole..Iaddend..Iadd.28. Thephotographic element recited in claim 10 wherein said heterocyclic ringis selected from the group consisting of thiazole, benzothiazole,naphthothiazole, thianaphtheno-7',6',4,5-thiazole, oxazole, benzoxazole,naphthoxazole, selenazole, benzoselenazole, naphthoselenazole,thiazoline, 2-quinoline, 4-quinoline, 1-isoquinoline, 3-isoquinoline,benzimidazole, 3,3-dialkylindolenine, 2-pyridine, 3,3-dialkylbenzindole,tetrazole, triazole, pyrimidine, and thiadiazole..Iaddend..Iadd.29. Thephotographic element recited in claim 28 wherein said X¹ and X² are thesame..Iaddend.